IT is difficult to over estimate the importance of the visual display in flight simulation. The resolution of the engineering problems associated with this subject have been given the highest priority by all simulator manufacturers over the past years. Until an effective and reliable visual system was available to give the correct cues to the pilots, simulation was confined to research and to a limited range of training manoeuvres. Visual simulation really came of age about six years ago when the Federal Aviation Agency in the USA first allowed training credits for manoeuvres such as engine out on takeoff and circling approach, reducing the training that could not be done in the simulator with visual system to a small percentage. Today, a pilot's transition training can occupy about twenty hours in the simulator, but only about two in the aircraft.